Tokyo University scientists have made use of chemically-induced quantum wells to cool portable electronics.
According to the scientists from the university’s Institute of Industrial Science (IIS), applying a bias voltage to quantum wells made of aluminum gallium arsenide, helps electrons shed some of their heat in a process called ‘evaporative cooling.’
Devices based on this principle could be added to electronic circuit boards using conventional semiconductor fabrication methods to help smartphones and laptops avoid heating issues.
As smartphones, tablets, and laptops become smaller and more powerful, the possibility of overheating is becoming an ever pressing concern.
Most electronics do make use of fans that are noisy, bulky, and have moving parts that eventually fail.
Now Tokyo’s IIS team has introduced a new, solid-state solution made from semiconductors that can be easily incorporated into smart phones or laptops.
“Modern portable devices have enabled the current information revolution,” explains co-author Marc Bescond.
“However, this miniaturization comes with inherent challenges from the waste heat produced.”
“Our new system allows for on-chip cooling using standard semiconductor fabrication processes.”
Quantum wells are nanoscale structures small enough to trap electrons.
The type of quantum well used in IIS’ research is called an asymmetric double-barrier heterostructure.
In these devices, very narrow gallium arsenide wells are separated by layers of aluminum gallium arsenide.
When the applied bias voltage is equal to energy of the quantum level inside the well, electrons can use resonant tunneling to easily pass through a barrier.
However, only the electrons with high kinetic energies will be able to continue past a second barrier.
Since the ‘hotter’ fast-moving electrons escape, while the ‘cooler’ slow electrons become trapped, the device becomes colder.
According to the scientists, this ‘Evaporative Cooling’ mechanism is analogous to the process that makes you feel cold when you step out of a swimming pool.
The water molecules with the most thermal energy are the first to evaporate off your skin, taking their heat with them.
Image and content: Pixabay/IIS-University of Tokyo